RESUMO
The current standard of care for diagnosis of severe intellectual disability (ID) and epileptic encephalopathy (EE) results in a diagnostic yield of â¼50%. Affected individuals nonetheless undergo multiple clinical evaluations and low-yield laboratory tests often referred to as a 'diagnostic odyssey'. This study was aimed at assessing the utility of clinical whole-exome sequencing (WES) in individuals with undiagnosed and severe forms of ID and EE, and the feasibility of its implementation in routine practice by a small regional genetic center. We performed WES in a cohort of 43 unrelated individuals with undiagnosed ID and/or EE. All individuals had undergone multiple clinical evaluations and diagnostic tests over the years, with no definitive diagnosis. Sequencing data analysis and interpretation were carried out at the local molecular genetics laboratory. The diagnostic rate of WES reached 32.5% (14 out of 43 individuals). Genetic diagnosis had a direct impact on clinical management in four families, including a prenatal diagnostic test in one family. Our data emphasize the clinical utility and feasibility of WES in individuals with undiagnosed forms of ID and EE and highlight the necessity of close collaborations between ordering physicians, molecular geneticists, bioinformaticians and researchers for accurate data interpretation.
Assuntos
Exoma/genética , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Transtornos do Neurodesenvolvimento/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/tendências , Epilepsia/diagnóstico , Epilepsia/genética , Feminino , Predisposição Genética para Doença/genética , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Masculino , Transtornos do Neurodesenvolvimento/diagnóstico , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
Infrared spectroscopy is used to investigate the transformation of carboxyl-terminated alkyl chains immobilized on a surface into succinimidyl ester-terminated chains by reaction with an aqueous solution of N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The acid chains are covalently grafted at the surface of hydrogenated porous silicon whose large specific surface area allows for assessing the activation yield in a semiquantitative way by infrared (IR) spectroscopy and detecting trace amounts of surface products and/or reaction products of small IR cross section. In this way, we rationalize the different reaction paths and optimize the reaction conditions to obtain as pure as possible succinimidyl ester-terminated surfaces. A diagram mapping the surface composition after activation was constructed by systematically varying the solution composition. Results are accounted for by NHS surface adsorption and a kinetic competition between the various EDC-induced surface reactions.